1. Field of the Invention
The present invention relates to an allocating mechanism for a weighing apparatus. More specifically, the present invention relates to an allocating mechanism that allocates objects to a plurality of paths before or after weighing the objects.
2. Background Information
Generally, in order to perform weighing at a high speed and with high precision, it is desirable to perform combination weighing. In combination weighing, the weight or the number of objects that are contained in each of a plurality of hoppers is calculated with a load cell (weight detector). A combination process is performed for each of the calculated values, such that a plurality of hoppers that generates a weight within a predetermined range is selected. The objects are then collected from these hoppers. In this manner, a collection of objects having a predetermined weight or number can be obtained.
A weighing apparatus that performs the above described combination weighing is disclosed in Japanese Laid-Open Patent Publication H7-306086. In this apparatus, the objects to be weighed (hereinafter referred to as objects) are dropped from a pool hopper into one of a pair of weighing hoppers. The pool hopper has two open/close gates, and is able to allocate the objects in the pair of weighing hoppers.
Although the objects are allocated before being weighed in the aforementioned publication, the objects can also be allocated at the time the objects are discharged after weighing the objects.
The operation of the allocating mechanism utilized in a conventional weighing apparatus is shown in FIG. 12. The allocating mechanism mainly includes a tubular sidewall 1, and two bottoms 2 and 3. As shown in FIG. 12(b) and FIG. 12(e), the bottoms 2 and 3 are opened and closed by an open/close means, which is not shown in the Figures. When the bottoms 2 and 3 are both closed, the sidewall 1 and the bottoms 2 and 3 form a storage space, in which the objects are stored. The allocating mechanism is disposed above the hoppers 4 and 5, which are two paths into which the objects are allocated. Here, the bottom 2 is opened when the objects in the storage space are to be dropped to the hopper 4. Similarly, the bottom 3 is opened when the objects are to be dropped from the bottom 3.
The allocating mechanism having a structure shown in FIG. 12 generally has little problem as long as the allocating mechanism handles certain objects. However, depending on the objects, the allocating mechanism may not be able to discharge the objects in the storage space fully to the hoppers 4 and 5. Accordingly, the calculation process, which is a process to be performed after the allocation, may be negatively affected. Additionally, since the objects that have been weighed in the previous process are not discharged fully in the subsequent process a situation in which the weight of the objects do not amount to the desired weight can occur.
For instance, in the case of objects such as sticky fermented soybeans, the objects may not fully be dropped to the hoppers 4 and 5 even after opening the bottoms 2 and 3. In other words, even when an operation to drop the objects P1 to the hopper 4 is performed as shown in FIG. 12(b), a portion of the objects P1a may adhere to the bottom 3 (see FIG. 12(c)). Alternatively, a portion of the objects P2a may remain on the bottom 2 (see FIG. 12(f)) even when an operation to drop the objects P2 to the hopper 5 is performed. When this happens the amount of the portions of the object P1a and P2a cannot be taken into consideration, and the precision in the amount of the object to be dropped in the hoppers 4 and 5 decreases.
In view of the above, there exists a need for an allocating mechanism for a weighing apparatus that overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
An object of the present invention is to provide an allocating mechanism for a weighing apparatus that temporarily stores objects and allocates the objects to a plurality of paths disposed below while reducing the amount of objects that remain in the weighing apparatus without being allocated to the paths.
An aspect of the present invention provides an allocating mechanism in a weighing apparatus. The allocating mechanism temporarily stores objects and allocates the objects to a plurality of paths disposed below after or before the objects are weighed. The allocating mechanism includes a sidewall, a bottom, driving means, and a controller. The bottom can, together with the sidewall, form a storage space in which the objects are stored. The driving means moves at least the sidewall. The controller rotates the sidewall by controlling the driving means such that a bottom end of the sidewall swings, thereby dropping the objects to one of the paths.
In this allocating mechanism, the objects that are conveyed are temporarily stored in the storage space that is formed by the sidewall and the bottom. Then, at least the sidewall is rotationally moved when the objects are dropped to one of the paths.
Conventionally, the allocating mechanism has a plurality of bottoms, such that the objects are allocated based on which bottom is open. Therefore, if the objects are stuck to the bottom that is closed, the objects cannot be dropped. However, the mechanism as set forth in the present invention has a sidewall that swings. Therefore, the sidewall can be moved so that the bottom is not below the sidewall. Accordingly, almost none of the objects remain on the bottom. Even if the objects are sticky, almost all the objects are dropped in one of the paths. Additionally, the path to which the objects are to be dropped can be controlled by changing the rotational direction of the sidewall.
The sidewall is moved rotationally such that a bottom end of the sidewall swings. Therefore, when an upper portion of the sidewall is an input portion, the input portion hardly moves. Accordingly, it is possible to prevent the objects from spilling during the allocation. That is, the cleanability of the weighing apparatus that has this allocating mechanism increases.
A second aspect of the present invention provides the allocating mechanism of the first mentioned aspect, wherein the sidewall is formed with a substantially vertical surface. Additionally, the bottom is formed with a substantially horizontal curved surface that does not hinder the rotation of the sidewall. Since the sidewall is formed of a substantially vertical surface, the objects can be prevented from being stuck to the sidewall. Additionally, since the bottom is substantially horizontal and the sidewall is substantially vertical, as the sidewall moves relative to the bottom, the sidewall functions as a scraper. Accordingly, objects that are stuck to the substantially horizontal bottom can be scraped off.
A third aspect of the present invention provides the allocating mechanism of either of the previously mentioned aspects, wherein the driving means moves both of the sidewall and the bottom, such that the sidewall and the bottom move away from each other. The bottom, as well as the sidewall, is moved along with the sidewall. Therefore, the amount of movement required in order to remove the bottom from below the sidewall becomes smaller. In particular, when the sidewall is moved rotationally, the inclination of the sidewall at the time of dropping the objects can be kept almost vertical. By utilizing a link mechanism, it is also possible to move both the sidewall and the bottom using one driving source, such that the sidewall and the bottom move away from each other.
A fourth aspect of the present invention provides the allocating mechanism set forth in the third mentioned aspect, wherein the storage space formed by the sidewall and the bottom is disposed above two of the paths so as to straddle the two paths. The storage space formed by the sidewall and the bottom is disposed so as to straddle the two paths to which the objects are allocated. Therefore, the amount of movement of the sidewall and the bottom can be kept small, regardless of the path to which the objects are allocated.
A fifth aspect of the present invention provides the allocating mechanism of any of the previously mentioned aspects, wherein the controller controls the driving means to vibrate the sidewall above the paths at the time of dropping the objects in one of the paths. The sidewall vibrates when the objects are dropped to the paths. Therefore, even if the objects are adhesive, are stuck to the sidewall, and do not come off easily, the vibration of the sidewall shakes off most of the objects. The vibration of the sidewall can be caused by small reciprocating movements of the sidewall, and also by banging on the sidewall.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.